windows-xp/Source/XPSP1/NT/drivers/parallel/parport2/daisychain.c

/*++

Copyright (C) Microsoft Corporation, 1993 - 1999

Module Name:

    par12843.c

Abstract:

    This is the main module for 1284.3 functionality.  These
      function enable the selection and deselection of 1284.3
      compatable devices on the parallel port.

    The devices can be selected and deselected IRQL <= DISPATCH_LEVEL 
    by calling IOCTL_INTERNAL_SELECT_DEVICE, or 'TrySelectDevice'.
    The first call is the simplest:  the IRP will be queued in the
    parallel port driver until the port is free and then it will 
    try to select the device with the given ID from the structure
    PARALLEL_1284_COMMAND.  If successful it will with a successful 
    status, otherwise it will return with an unsuccessful status.
    The class driver may cancel this IRP at any time which serves 
    as a mechanism to timeout an allocate request.

    The 'TrySelectDevice' call returns immediately from the port
    driver with a TRUE status if the port was allocated and the
    device was able to be selected or a FALSE status if the port 
    was either busy or the device was not able to be selected.

    Once the device is selected, the port is owned by the selecting class
    driver until a 'DeselectDevice' call is made.  This deselects the
    device and also releases the port and wakes up the next caller.

Author:

    Don E. Redford  3-Mar-1998

Environment:

    Kernel mode

Revision History :


--*/

#include "pch.h"

ULONG
PptInitiate1284_3(
    IN  PVOID   Extension
    );

NTSTATUS
PptTrySelectDevice(
    IN  PVOID   Context,
    IN  PVOID   TrySelectCommand
    );

NTSTATUS
PptDeselectDevice(
    IN  PVOID   Context,
    IN  PVOID   DeselectCommand
    );

ULONG
Ppt1284_3AssignAddress(
    IN  PFDO_EXTENSION    DeviceExtension
    );

BOOLEAN
PptSend1284_3Command(
    IN  PUCHAR  CurrentPort,
    IN  UCHAR   Command
    );

BOOLEAN
PptCheckIfStl1284_3(
    IN PFDO_EXTENSION    DeviceExtension,
    IN ULONG    ulDaisyIndex,
    IN BOOLEAN  bNoStrobe
    );

BOOLEAN
PptCheckIfNon1284_3Present(
    IN PFDO_EXTENSION    Extension
    );

BOOLEAN
PptCheckIfStlProductId(
    IN PFDO_EXTENSION    Extension,
    IN ULONG   ulDaisyIndex
    );
//
// Beginning of functions
//

ULONG
PptInitiate1284_3(
    IN  PVOID   Extension
    )

/*++

Routine Description:

    This routine initializes all of the 1284.3 devices out on the
    given parallel port.  It does this by assigning 1284.3 addresses to
    each device on the port.

Arguments:

    Extensioon    - Device extension structure.

Return Value:

    None.

--*/

{
    ULONG deviceCount1 = 0;
    ULONG deviceCount2 = 0;
    ULONG loopCount    = 0;
    ULONG maxTries     = 3; // picked 3 out of thin air as a "reasonable" value

    // Send command to assign addresses and count number of 1284.3 daisy chain devices 
    // Try multiple times to make sure we get the same count
    do {

        KeStallExecutionProcessor( 5 );
        deviceCount1 = Ppt1284_3AssignAddress( Extension );

        KeStallExecutionProcessor( 5 );
        deviceCount2 = Ppt1284_3AssignAddress( Extension );

        if( deviceCount1 != deviceCount2 ) {
            DD((PCE)Extension,DDW,"PptInitiate1284_3 - count unstable\n");
            PptAssert(deviceCount1 == deviceCount2);
        }

    } while( (deviceCount1 != deviceCount2) && (++loopCount < maxTries) );

    return deviceCount2;
}

NTSTATUS
PptTrySelectDevice(
    IN  PVOID   Context,
    IN  PVOID   TrySelectCommand
    )
/*++

Routine Description:

    This routine first tries to allocate the port.  If successful
      it will then try to select  the device with the ID given.

Arguments:

    Extension   -   Driver extension.
    Device      -   1284.3 Device Id.
    Command     -   Command to know whether to allocate the port

Return Value:

    TRUE            -  Able to allocate the port and select the device
    FALSE           -  1: Invalid ID    2: Not able to allocate port    3: Not able to select device

--*/
{
    NTSTATUS                    Status = STATUS_SUCCESS;
    PFDO_EXTENSION           Extension = Context;
    PPARALLEL_1284_COMMAND      Command = TrySelectCommand;
    BOOLEAN                     success = FALSE;
    SYNCHRONIZED_COUNT_CONTEXT  SyncContext;
    KIRQL                       CancelIrql;
    UCHAR                       i, DeviceID;

    if( ( Command->CommandFlags & PAR_LEGACY_ZIP_DRIVE ) ||
        ( Command->ID == DOT3_LEGACY_ZIP_ID )) {
        Status = PptTrySelectLegacyZip(Context, TrySelectCommand);
        DD((PCE)Extension,DDT,"PptTrySelectDevice - LegacyZip - status=%x\n",Status);
        return Status;
    }

    // get device ID to select
    DeviceID = Command->ID;
            
    // validate parameters - we will accept:
    //   - a Dot3 device with a valid DeviceID
    //   - an End-of-Chain device indicated by the PAR_END_OF_CHAIN_DEVICE flag, or
    //   - an End-of-Chain device indicated by a DeviceID value one past the last Dot3 device

    if ( !(Command->CommandFlags & PAR_END_OF_CHAIN_DEVICE) && DeviceID > Extension->PnpInfo.Ieee1284_3DeviceCount ) {
                
        // Requested device is not flagged as End-of-Chain device and DeviceID
        //   is more than one past the end of the Dot3 Devices, so FAIL the IRP
        DD((PCE)Extension,DDE,"PptTrySelectDevice - FAIL - invalid DeviceID parameter\n",DeviceID);
        PptAssertMsg("PptTrySelectDevice - FAIL - invalid DeviceID parameter",FALSE);
        Status = STATUS_INVALID_PARAMETER;
                
    } else {
                
        //
        // Request appears valid
        //

        // test to see if we need to grab port
        if( Command->CommandFlags & PAR_HAVE_PORT_KEEP_PORT ) {

            //
            // requester has already acquired port, just do a SELECT
            //
            if ( !(Command->CommandFlags & PAR_END_OF_CHAIN_DEVICE) &&
                    DeviceID < Extension->PnpInfo.Ieee1284_3DeviceCount ) {

                // SELECT the device
                for ( i = 0; i < PptDot3Retries && !success; i++ ) {
                    // Send command to to select device in compatability mode
                    success = PptSend1284_3Command( Extension->PortInfo.Controller, (UCHAR)(CPP_SELECT | DeviceID) );
                    // Stall a little in case we have to retry
                    KeStallExecutionProcessor( 5 );
                }                

                if ( success ) {
                    DD((PCE)Extension,DDT,"PptTrySelectDevice - had port - SUCCESS\n");
                    Status = STATUS_SUCCESS;
                } else {
                    DD((PCE)Extension,DDW,"PptTrySelectDevice - FAIL\n");
                    Status = STATUS_UNSUCCESSFUL;
                }
            } else {
                // End-of-Chain device, no SELECT required, SUCCEED the request
                DD((PCE)Extension,DDT,"PptTrySelectDevice - EOC\n");
                Status = STATUS_SUCCESS;
            }

        } else {

            // Don't have the port

            //
            // Try to acquire port and select device
            //
            IoAcquireCancelSpinLock(&CancelIrql);
                
            SyncContext.Count = &Extension->WorkQueueCount;
                    
            if (Extension->InterruptRefCount) {
                KeSynchronizeExecution(Extension->InterruptObject, PptSynchronizedIncrement, &SyncContext);
            } else {
                PptSynchronizedIncrement(&SyncContext);
            }
                    
            if (SyncContext.NewCount) {
                // Port is busy, queue request
                DD((PCE)Extension,DDT,"PptTrySelectDevice - Port Busy - Request Queued\n");
                IoReleaseCancelSpinLock(CancelIrql);
                Status = STATUS_PENDING;

            } else {

                IoReleaseCancelSpinLock(CancelIrql);
                        
                // Port is acquired
                DD((PCE)Extension,DDT,"PptTrySelectDevice - Port Acquired\n");

                Extension->WmiPortAllocFreeCounts.PortAllocates++;

                if ( !(Command->CommandFlags & PAR_END_OF_CHAIN_DEVICE) && DeviceID < Extension->PnpInfo.Ieee1284_3DeviceCount ) {
                            
                    // SELECT the device
                    for ( i = 0; i < PptDot3Retries && !success; i++ ) {
                        // Send command to to select device in compatability mode
                        success = PptSend1284_3Command( Extension->PortInfo.Controller, (UCHAR)(CPP_SELECT | DeviceID) );
                        // Stall a little in case we have to retry
                        KeStallExecutionProcessor( 5 );
                    }                

                    if ( success ) {
                        DD((PCE)Extension,DDT,"PptTrySelectDevice - SUCCESS\n");
                        Status = STATUS_SUCCESS;
                    } else {
                        DD((PCE)Extension,DDW,"PptTrySelectDevice - FAILED\n");

                        // RMT - 000831 - do we still have the port locked!?! - did we hang the port?

                        Status = STATUS_UNSUCCESSFUL;
                    }

                } else {
                    // End-of-Chain device, no SELECT required, SUCCEED the request
                    DD((PCE)Extension,DDT,"PptTrySelectDevice - EOC2\n");
                    Status = STATUS_SUCCESS;
                }

            }  // endif - test for port busy
                    
        } // endif - test if already have port

    } // endif - test for valid parameters

    return Status;
}

NTSTATUS
PptDeselectDevice(
    IN  PVOID   Context,
    IN  PVOID   DeselectCommand
    )
    
/*++

Routine Description:

    This routine deselects the current device and then frees the port

Arguments:


Return Value:

    TRUE            -  Able to deselect the device and free the port
    FALSE           -  1: Invalid ID    2: Not able to deselect the drive

--*/

{
    NTSTATUS                Status = STATUS_SUCCESS;
    PFDO_EXTENSION       fdx = Context;
    PPARALLEL_1284_COMMAND  Command = DeselectCommand;
    BOOLEAN                 success = FALSE;
    UCHAR                   i, DeviceID;

    if( ( Command->CommandFlags & PAR_LEGACY_ZIP_DRIVE ) ||
        ( Command->ID == DOT3_LEGACY_ZIP_ID ) ) {
        return PptDeselectLegacyZip( Context, DeselectCommand );
    }

    // get device ID to deselect
    DeviceID = Command->ID;

    // validate ID
    if ( !(Command->CommandFlags & PAR_END_OF_CHAIN_DEVICE) && DeviceID > fdx->PnpInfo.Ieee1284_3DeviceCount ) {

        // not End-of-Chain device and Dot3 DeviceID is invalid
        DD((PCE)fdx,DDE,"PptDeselectDevice - ID=%d - FAIL - invalid parameter\n",DeviceID);
        Status = STATUS_INVALID_PARAMETER;
                
    } else {
                
        // Check for End-of-Chain device
        if ( !(Command->CommandFlags & PAR_END_OF_CHAIN_DEVICE) &&
                DeviceID < fdx->PnpInfo.Ieee1284_3DeviceCount ) {
                    
            // first deselect the device 
            for ( i = 0; i < PptDot3Retries && !success; i++ ) {
                success = PptSend1284_3Command( fdx->PortInfo.Controller, (UCHAR)CPP_DESELECT );
                // Stall a little in case we have to retry
                KeStallExecutionProcessor( 5 );
            }

            if ( success ) {
                // Deselecting device was a success
                DD((PCE)fdx,DDT,"PptDeselectDevice\n");

                // check if requester wants to keep port or free port
                if( !(Command->CommandFlags & PAR_HAVE_PORT_KEEP_PORT) ) {
                    PptFreePort( fdx );
                }
                Status = STATUS_SUCCESS;
                        
            } else {
                // Unable to deselect device, something went very wrong,
                //   port is now in an unknown/blocked state
                DD((PCE)fdx,DDE,"PptDeselectDevice - ID=%d - FAIL\n",DeviceID);
                PptAssertMsg("PptDeselectDevice - FAIL - port in unknown state",FALSE);
                Status = STATUS_UNSUCCESSFUL;
            }
                    
        } else {

            // this is End-of-Chain device so no deselect neccessary
            DD((PCE)fdx,DDT,"PptDeselectDevice - End-of-Chain - SUCCESS\n",DeviceID);

            // check if requester wants to keep port or free port
            if( !(Command->CommandFlags & PAR_HAVE_PORT_KEEP_PORT) ) {
                PptFreePort( fdx );
            }
            Status = STATUS_SUCCESS;

        }  // endif - Check if End Of Chain

    } // endif - Validate ID

    return Status;
}


ULONG
Ppt1284_3AssignAddress(
    IN  PFDO_EXTENSION    DeviceExtension
    )

/*++

Routine Description:

    This routine initializes the 1284_3 bus.

Arguments:

    DeviceExtension    - Supplies Device Extension structure of the driver.

Return Value:

    Number of 1284.3 devices out there at the given address.

--*/

{

    //UCHAR  i, ii, value, newvalue, status;
    UCHAR  i, value, newvalue, status;
    PUCHAR CurrentPort, CurrentStatus, CurrentControl;
    ULONG  Delay = 5;
    UCHAR  number = 0;
    BOOLEAN lastdevice = FALSE;
    UCHAR   idx;

    CurrentPort = DeviceExtension->PortInfo.Controller;
    CurrentStatus  = CurrentPort + 1;
    CurrentControl = CurrentPort + 2;

    // get current ctl reg
    value = P5ReadPortUchar( CurrentControl );

    // make sure 1284.3 devices do not get reseted
    newvalue = (UCHAR)((value & ~DCR_SELECT_IN) | DCR_NOT_INIT);

    // make sure we can write
    newvalue = (UCHAR)(newvalue & ~DCR_DIRECTION);
    P5WritePortUchar( CurrentControl, newvalue );    // make sure we can write 

    // bring nStrobe high
    P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );

    // send first four bytes of the 1284.3 mode qualifier sequence out
    for ( i = 0; i < MODE_LEN_1284_3 - 3; i++ ) {
        P5WritePortUchar( CurrentPort, ModeQualifier[i] );
        KeStallExecutionProcessor( Delay );
    }

    // check for correct status
    status = P5ReadPortUchar( CurrentStatus );

    if ( (status & (UCHAR)0xb8 ) 
         == ( DSR_NOT_BUSY | DSR_PERROR | DSR_SELECT | DSR_NOT_FAULT )) {

        // continue with fifth byte of mode qualifier
        P5WritePortUchar( CurrentPort, ModeQualifier[4] );
        KeStallExecutionProcessor( Delay );

        // check for correct status
        status = P5ReadPortUchar( CurrentStatus );

        // note busy is high too but is opposite so we see it as a low
        if (( status & (UCHAR) 0xb8 ) == (DSR_SELECT | DSR_NOT_FAULT)) {

            // continue with sixth byte
            P5WritePortUchar( CurrentPort, ModeQualifier[5] );
            KeStallExecutionProcessor( Delay );

            // check for correct status
            status = P5ReadPortUchar( CurrentStatus );

            // if status is valid there is a device out there responding
            if ((status & (UCHAR) 0x30 ) == ( DSR_PERROR | DSR_SELECT )) {        

                // Device is out there
                KeStallExecutionProcessor( Delay );

                while ( number < 4 && !lastdevice ) {

                    // Asssign address byte
                    P5WritePortUchar( CurrentPort, number );
                    number = (UCHAR)(number + 1);

                    KeStallExecutionProcessor( Delay );                    // wait a bit
                    if ( (P5ReadPortUchar( CurrentStatus ) & (UCHAR)DSR_NOT_BUSY ) == 0 ) {
                        // we saw last device
                        lastdevice = TRUE;    
                    }

                    P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );    // bring nStrobe high
                    P5WritePortUchar( CurrentControl, (UCHAR)(newvalue | DCR_STROBE) );    // bring nStrobe low
                    KeStallExecutionProcessor( Delay );        // wait a bit
                    P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );    // bring nStrobe high
                    KeStallExecutionProcessor( Delay );        // wait a bit
                }

                // last byte
                P5WritePortUchar( CurrentPort, ModeQualifier[6] );

                if ( number ) {
                    BOOLEAN bStlNon1284_3Found ;
                    BOOLEAN bStlNon1284_3Valid ;
                    bStlNon1284_3Found = PptCheckIfNon1284_3Present(DeviceExtension);
                    bStlNon1284_3Valid = FALSE ;
                    // as the earlier 1284 spec does not give the
                    // lastdevice status is BSY, number needs to
                    // be corrected in such cases
                    for ( idx = 0 ; idx < number ; idx++ ) {
                        if ( TRUE == PptCheckIfStl1284_3(DeviceExtension, idx, bStlNon1284_3Found ) ) {
                            continue ;
                        }
                        if ( TRUE == bStlNon1284_3Found ) {
                            if ( TRUE == PptCheckIfStlProductId(DeviceExtension, idx) ) {
                                bStlNon1284_3Valid = TRUE ;
                                continue ;
                            }
                        }
                        break ;
                    }
                    if ( TRUE == bStlNon1284_3Valid ) {
                        // we alter the count only if old adapters
                        // are in the chain
                        number = idx;
                    }
                }

            } // Third status

        } // Second status

    } // First status

    P5WritePortUchar( CurrentControl, value );    // restore everything

    // returns last device ID + 1 or number of devices out there
    return ( (ULONG)number );

}

BOOLEAN
PptCheckIfNon1284_3Present(
    IN PFDO_EXTENSION    Extension
    )
/*++

Routine Description:

    Indicates whether one of the devices of the earlier
    specification is present in the chain.


Arguments:

    Extension   - Device Extension structure


Return Value:

    TRUE    : Atleast one of the adapters are of earlier spec.
    FALSE   : None of the adapters of the earlier spec.

--*/
{
    BOOLEAN bReturnValue = FALSE ;
    UCHAR   i, value, newvalue, status;
    ULONG   Delay = 3;
    PUCHAR  CurrentPort, CurrentStatus, CurrentControl;
    UCHAR   ucAckStatus ;

    CurrentPort = Extension->PortInfo.Controller;
    CurrentStatus  = CurrentPort + 1;
    CurrentControl = CurrentPort + 2;

    // get current ctl reg
    value = P5ReadPortUchar( CurrentControl );

    // make sure 1284.3 devices do not get reseted
    newvalue = (UCHAR)((value & ~DCR_SELECT_IN) | DCR_NOT_INIT);

    // make sure we can write
    newvalue = (UCHAR)(newvalue & ~DCR_DIRECTION);
    P5WritePortUchar( CurrentControl, newvalue );    // make sure we can write 

    // bring nStrobe high
    P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );

    // send first four bytes of the 1284.3 mode qualifier sequence out
    for ( i = 0; i < MODE_LEN_1284_3 - 3; i++ ) {
        P5WritePortUchar( CurrentPort, ModeQualifier[i] );
        KeStallExecutionProcessor( Delay );
    }

    // check for correct status
    status = P5ReadPortUchar( CurrentStatus );

    if ( (status & (UCHAR)0xb8 ) 
         == ( DSR_NOT_BUSY | DSR_PERROR | DSR_SELECT | DSR_NOT_FAULT )) {

        ucAckStatus = status & 0x40 ;

        // continue with fifth byte of mode qualifier
        P5WritePortUchar( CurrentPort, ModeQualifier[4] );
        KeStallExecutionProcessor( Delay );

        // check for correct status
        status = P5ReadPortUchar( CurrentStatus );

        // note busy is high too but is opposite so we see it as a low
        if (( status & (UCHAR) 0xb8 ) == (DSR_SELECT | DSR_NOT_FAULT)) {

            if ( ucAckStatus != ( status & 0x40 ) ) {

                // save current ack status
                ucAckStatus = status & 0x40 ;

                // continue with sixth byte
                P5WritePortUchar( CurrentPort, ModeQualifier[5] );
                KeStallExecutionProcessor( Delay );

                // check for correct status
                status = P5ReadPortUchar( CurrentStatus );

                // if status is valid there is a device out there responding
                if ((status & (UCHAR) 0x30 ) == ( DSR_PERROR | DSR_SELECT )) {        

                    bReturnValue = TRUE ;

                } // Third status

            } // ack of earlier adapters not seen

            // last byte
            P5WritePortUchar( CurrentPort, ModeQualifier[6] );

        } // Second status

    } // First status

    P5WritePortUchar( CurrentControl, value );    // restore everything

    return bReturnValue ;
} // PptCheckIfNon1284_3Present


// Define 1284 Commands
#define CPP_QUERY_PRODID    0x10

// 1284 related SHTL prod id equates
#define SHTL_EPAT_PRODID    0xAAFF
#define SHTL_EPST_PRODID    0xA8FF

BOOLEAN
PptCheckIfStl1284_3(
    IN PFDO_EXTENSION    DeviceExtension,
    IN ULONG    ulDaisyIndex,
    IN BOOLEAN  bNoStrobe
    )
/*++

Routine Description:

    This function checks to see whether the device indicated
    is a Shuttle 1284_3 type of device. 

Arguments:

    Extension       - Device extension structure.

    ulDaisyIndex    - The daisy chain id of the device that
                      this function will check on.

    bNoStrobe       - If set, indicates that the query
                      Ep1284 command issued by this function
                      need not assert strobe to latch the
                      command.

Return Value:

    TRUE            - Yes. Device is Shuttle 1284_3 type of device.
    FALSE           - No. This may mean that this device is either
                      non-shuttle or Shuttle non-1284_3 type of
                      device.

--*/
{
    BOOLEAN bReturnValue = FALSE ;
    UCHAR   i, value, newvalue, status;
    ULONG   Delay = 3;
    UCHAR   ucExpectedPattern ;
    UCHAR   ucReadValue, ucReadPattern;
    PUCHAR  CurrentPort, CurrentStatus, CurrentControl;

    CurrentPort = DeviceExtension->PortInfo.Controller;
    CurrentStatus  = CurrentPort + 1;
    CurrentControl = CurrentPort + 2;

    // get current ctl reg
    value = P5ReadPortUchar( CurrentControl );

    // make sure 1284.3 devices do not get reseted
    newvalue = (UCHAR)((value & ~DCR_SELECT_IN) | DCR_NOT_INIT);

    // make sure we can write
    newvalue = (UCHAR)(newvalue & ~DCR_DIRECTION);
    P5WritePortUchar( CurrentControl, newvalue );    // make sure we can write 

    // bring nStrobe high
    P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );

    // send first four bytes of the 1284.3 mode qualifier sequence out
    for ( i = 0; i < MODE_LEN_1284_3 - 3; i++ ) {
        P5WritePortUchar( CurrentPort, ModeQualifier[i] );
        KeStallExecutionProcessor( Delay );
    }

    // check for correct status
    status = P5ReadPortUchar( CurrentStatus );

    if ( (status & (UCHAR)0xb8 ) 
         == ( DSR_NOT_BUSY | DSR_PERROR | DSR_SELECT | DSR_NOT_FAULT )) {

        // continue with fifth byte of mode qualifier
        P5WritePortUchar( CurrentPort, ModeQualifier[4] );
        KeStallExecutionProcessor( Delay );

        // check for correct status
        status = P5ReadPortUchar( CurrentStatus );

        // note busy is high too but is opposite so we see it as a low
        if (( status & (UCHAR) 0xb8 ) == (DSR_SELECT | DSR_NOT_FAULT)) {

            // continue with sixth byte
            P5WritePortUchar( CurrentPort, ModeQualifier[5] );
            KeStallExecutionProcessor( Delay );

            // check for correct status
            status = P5ReadPortUchar( CurrentStatus );

            // if status is valid there is a device out there responding
            if ((status & (UCHAR) 0x30 ) == ( DSR_PERROR | DSR_SELECT )) {        

                // Device is out there
                KeStallExecutionProcessor( Delay );

                // issue shuttle specific CPP command
                P5WritePortUchar( CurrentPort, (UCHAR) ( 0x88 | ulDaisyIndex ) );
                KeStallExecutionProcessor( Delay );        // wait a bit

                if ( ulDaisyIndex && ( bNoStrobe == FALSE ) ) {

                    P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );    // bring nStrobe high
                    P5WritePortUchar( CurrentControl, (UCHAR)(newvalue | DCR_STROBE) );    // bring nStrobe low
                    KeStallExecutionProcessor( Delay );        // wait a bit
                    P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );    // bring nStrobe high
                    KeStallExecutionProcessor( Delay );        // wait a bit

                }

                ucExpectedPattern = 0xF0 ;
                bReturnValue = TRUE ;

                while ( ucExpectedPattern ) {

                    KeStallExecutionProcessor( Delay );        // wait a bit
                    P5WritePortUchar( CurrentPort, (UCHAR) (0x80 | ulDaisyIndex )) ;

                    KeStallExecutionProcessor( Delay );        // wait a bit
                    P5WritePortUchar( CurrentPort, (UCHAR) (0x88 | ulDaisyIndex )) ;

                    KeStallExecutionProcessor( Delay );        // wait a bit
                    ucReadValue = P5ReadPortUchar( CurrentStatus ) ;
                    ucReadPattern = ( ucReadValue << 1 ) & 0x70 ;
                    ucReadPattern |= ( ucReadValue & 0x80 ) ;

                    if ( ucReadPattern != ucExpectedPattern ) {
                        // not Shuttle 1284_3 behaviour
                        bReturnValue = FALSE ;
                        break ;
                    }

                    ucExpectedPattern -= 0x10 ;
                }


                // last byte
                P5WritePortUchar( CurrentPort, ModeQualifier[6] );

            } // Third status

        } // Second status

    } // First status

    P5WritePortUchar( CurrentControl, value );    // restore everything

    return bReturnValue ;
} // end  PptCheckIfStl1284_3()

BOOLEAN
PptCheckIfStlProductId(
    IN PFDO_EXTENSION    DeviceExtension,
    IN ULONG   ulDaisyIndex
    )
/*++

Routine Description:

    This function checks to see whether the device indicated
    is a Shuttle non-1284_3 type of device. 

Arguments:

    Extension       - Device extension structure.

    ulDaisyIndex    - The daisy chain id of the device that
                      this function will check on.

Return Value:

    TRUE            - Yes. Device is Shuttle non-1284_3 type of device.
    FALSE           - No. This may mean that this device is 
                      non-shuttle.

--*/
{
    BOOLEAN bReturnValue = FALSE ;
    UCHAR   i, value, newvalue, status;
    ULONG   Delay = 3;
    UCHAR   ucProdIdHiByteHiNibble, ucProdIdHiByteLoNibble ;
    UCHAR   ucProdIdLoByteHiNibble, ucProdIdLoByteLoNibble ;
    UCHAR   ucProdIdHiByte, ucProdIdLoByte ;
    USHORT  usProdId ;
    PUCHAR  CurrentPort, CurrentStatus, CurrentControl;

    CurrentPort = DeviceExtension->PortInfo.Controller;
    CurrentStatus  = CurrentPort + 1;
    CurrentControl = CurrentPort + 2;

    // get current ctl reg
    value = P5ReadPortUchar( CurrentControl );

    // make sure 1284.3 devices do not get reseted
    newvalue = (UCHAR)((value & ~DCR_SELECT_IN) | DCR_NOT_INIT);

    // make sure we can write
    newvalue = (UCHAR)(newvalue & ~DCR_DIRECTION);
    P5WritePortUchar( CurrentControl, newvalue );    // make sure we can write 

    // bring nStrobe high
    P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );

    // send first four bytes of the 1284.3 mode qualifier sequence out
    for ( i = 0; i < MODE_LEN_1284_3 - 3; i++ ) {
        P5WritePortUchar( CurrentPort, ModeQualifier[i] );
        KeStallExecutionProcessor( Delay );
    }

    // check for correct status
    status = P5ReadPortUchar( CurrentStatus );

    if ( (status & (UCHAR)0xb8 ) 
         == ( DSR_NOT_BUSY | DSR_PERROR | DSR_SELECT | DSR_NOT_FAULT )) {

        // continue with fifth byte of mode qualifier
        P5WritePortUchar( CurrentPort, ModeQualifier[4] );
        KeStallExecutionProcessor( Delay );

        // check for correct status
        status = P5ReadPortUchar( CurrentStatus );

        // note busy is high too but is opposite so we see it as a low
        if (( status & (UCHAR) 0xb8 ) == (DSR_SELECT | DSR_NOT_FAULT)) {

            // continue with sixth byte
            P5WritePortUchar( CurrentPort, ModeQualifier[5] );
            KeStallExecutionProcessor( Delay );

            // check for correct status
            status = P5ReadPortUchar( CurrentStatus );

            // if status is valid there is a device out there responding
            if ((status & (UCHAR) 0x30 ) == ( DSR_PERROR | DSR_SELECT )) {

                P5WritePortUchar ( CurrentPort, (UCHAR) (CPP_QUERY_PRODID | ulDaisyIndex )) ;
                KeStallExecutionProcessor( Delay );

                // Device is out there
                KeStallExecutionProcessor( Delay );
                ucProdIdLoByteHiNibble = P5ReadPortUchar( CurrentStatus ) ;
                ucProdIdLoByteHiNibble &= 0xF0 ;

                KeStallExecutionProcessor( Delay );
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue | DCR_STROBE) );    // bring nStrobe low
                KeStallExecutionProcessor( Delay );        // wait a bit
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );    // bring nStrobe high
                KeStallExecutionProcessor( Delay );        // wait a bit

                ucProdIdLoByteLoNibble = P5ReadPortUchar( CurrentStatus ) ;
                ucProdIdLoByteLoNibble >>= 4 ;
                ucProdIdLoByte = ucProdIdLoByteHiNibble | ucProdIdLoByteLoNibble ;

                KeStallExecutionProcessor( Delay );
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue | DCR_STROBE) );    // bring nStrobe low
                KeStallExecutionProcessor( Delay );        // wait a bit
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );    // bring nStrobe high
                KeStallExecutionProcessor( Delay );        // wait a bit

                ucProdIdHiByteHiNibble = P5ReadPortUchar( CurrentStatus ) ;
                ucProdIdHiByteHiNibble &= 0xF0 ;

                KeStallExecutionProcessor( Delay );
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue | DCR_STROBE) );    // bring nStrobe low
                KeStallExecutionProcessor( Delay );        // wait a bit
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );    // bring nStrobe high
                KeStallExecutionProcessor( Delay );        // wait a bit

                ucProdIdHiByteLoNibble = P5ReadPortUchar( CurrentStatus ) ;
                ucProdIdHiByteLoNibble >>= 4 ;
                ucProdIdHiByte = ucProdIdHiByteHiNibble | ucProdIdHiByteLoNibble ;

                // issue the last strobe
                KeStallExecutionProcessor( Delay );
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue | DCR_STROBE) );    // bring nStrobe low
                KeStallExecutionProcessor( Delay );        // wait a bit
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );    // bring nStrobe high
                KeStallExecutionProcessor( Delay );        // wait a bit

                usProdId = ( ucProdIdHiByte << 8 ) | ucProdIdLoByte ;

                if ( ( SHTL_EPAT_PRODID == usProdId ) ||\
                     ( SHTL_EPST_PRODID == usProdId ) ) {
                    // one of the devices that conform to the earlier
                    // draft is found
                    bReturnValue = TRUE ;
                }

                // last byte
                P5WritePortUchar( CurrentPort, ModeQualifier[6] );

            } // Third status

        } // Second status

    } // First status

    P5WritePortUchar( CurrentControl, value );    // restore everything

    return bReturnValue ;
} // end  PptCheckIfStlProductId()

BOOLEAN
PptSend1284_3Command(
    IN  PUCHAR  CurrentPort,
    IN  UCHAR   Command
    )
/*++

Routine Description:

    This routine sends the 1284_3 Command given to it
    down the parallel bus.

Arguments:


Return Value:

    None.

--*/
{
    UCHAR  i, value, newvalue, test;//, status;
    ULONG  ii;
    PUCHAR CurrentStatus, CurrentControl;
    ULONG  Delay = 3;
    BOOLEAN success = FALSE;

    CurrentStatus  = CurrentPort + 1;
    CurrentControl = CurrentPort + 2;

    // Get Upper 4 bits to see what Command it is
    test = (UCHAR)(Command & (UCHAR)CPP_COMMAND_FILTER);

    // get current ctl reg
    value = P5ReadPortUchar( CurrentControl );
    
    // make sure 1284.3 devices do not get reseted
    newvalue = (UCHAR)((value & ~DCR_SELECT_IN) | DCR_NOT_INIT);
    
    // make sure we can write
    newvalue = (UCHAR)(newvalue & ~DCR_DIRECTION);
    P5WritePortUchar( CurrentControl, newvalue );       // make sure we can write 
    
    // bring nStrobe high
    P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );
    KeStallExecutionProcessor( Delay );
    
    // send first four bytes of the 1284.3 mode qualifier sequence out
    for ( i = 0; i < MODE_LEN_1284_3 - 3; i++ ) {
        P5WritePortUchar( CurrentPort, ModeQualifier[i] );
        KeStallExecutionProcessor( Delay );
    }
    
    // wait up to 5 us : Spec says about 2 but we will be lienient
    if (CHECK_DSR(CurrentPort, INACTIVE, DONT_CARE, ACTIVE, ACTIVE, ACTIVE, 5 )) {

        // continue with fifth byte of mode qualifier
        P5WritePortUchar( CurrentPort, ModeQualifier[4] );
        KeStallExecutionProcessor( Delay );
        
        // wait up to 5 us : Spec says about 2 but we will be lienient
        if (CHECK_DSR(CurrentPort, ACTIVE, DONT_CARE, INACTIVE, ACTIVE, ACTIVE, 5 )) {

            // continue with sixth byte
            P5WritePortUchar( CurrentPort, ModeQualifier[5] );
            KeStallExecutionProcessor( Delay );
            
            // wait up to 5 us : Spec says about 2 but we will be lienient
            if (CHECK_DSR(CurrentPort, DONT_CARE, DONT_CARE, ACTIVE, ACTIVE, DONT_CARE, 5 )) {

                // Device is out there
                
                KeStallExecutionProcessor( Delay );

                // Command byte
                P5WritePortUchar( CurrentPort, Command );
                KeStallExecutionProcessor( Delay );        // wait a bit

                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );    // bring nStrobe high
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue | DCR_STROBE) );    // bring nStrobe low
                KeStallExecutionProcessor( Delay );        // wait a bit

                // NOTE NOTE NOTE
                // Assertion of strobe to be done ONLY after checking for the
                // FAULT feedback, as per the 1284_3 specification.

                // Selection does not work correctly yet to be able to check for lines
                switch ( test ) {
                    
                case CPP_SELECT:
                    // Check to make sure we are selected

                    // wait for upto 250 micro Secs for for selection time out.
                    for ( ii = 25000; ii > 0; ii-- ) {
                        
                        if ( ( P5ReadPortUchar( CurrentStatus ) & DSR_NOT_FAULT ) == DSR_NOT_FAULT ) {
                            // selection...
                            success = TRUE;
                            break;
                        }
                    }
                    break;

                case CPP_DESELECT:
                    // Check to make sure we are deselected                    

                    // wait for upto 250 micro Secs for for deselection time out.
                    for ( ii = 25000; ii > 0; ii-- ) {

                        if ( (P5ReadPortUchar( CurrentStatus ) & DSR_NOT_FAULT) != DSR_NOT_FAULT ) {
                            // deselection...
                            success = TRUE;
                            break;
                        }
                    }
                    break;

                default :
                    // there is a device out there and Command completed sucessfully
                    KeStallExecutionProcessor( Delay );        // wait a bit
                    success = TRUE;
                    break;

                } // End Switch

                // NOTE NOTE NOTE
                // the strobe is de-asserted now and the command is completed here
                P5WritePortUchar( CurrentControl, (UCHAR)(newvalue & ~DCR_STROBE) );    // bring nStrobe high
                KeStallExecutionProcessor( Delay );        // wait a bit

                // last byte
                P5WritePortUchar( CurrentPort, ModeQualifier[6] );

            } // Third status
            
        } // Second status
        
    } // First status

    P5WritePortUchar( CurrentControl, value );    // restore everything

    // return TRUE if command succeeded, FALSE otherwise
    return success;
}


BOOLEAN
ParSelectDevice(
    IN  PPDO_EXTENSION  Pdx,
    IN  BOOLEAN         HavePort
    )

/*++

Routine Description:

    This routine acquires the ParPort and selects a 1284.3 device

Arguments:

    Pdx   - Supplies the device extension.

    HavePort    - TRUE  indicates that caller has already acquired port
                    so we should only do a SELECT_DEVICE
                - FALSE indicates that caller has not already acquired port
                    so we should do a combination ACQUIRE_PORT/SELECT_DEVICE

Return Value:

    TRUE    - success - the device was selected (and port acquired if needed)
    FALSE   - failure

--*/
{
    NTSTATUS                    status;
    PDEVICE_OBJECT              pPortDeviceObject;
    PARALLEL_1284_COMMAND       par1284Command;
    LARGE_INTEGER               timeOut;
    enum _PdoType               pdoType;

    //
    // Initialize command structure and extract parameters from the DeviceExtension
    //

    // reserved - always set to 0
    par1284Command.Port = 0;

    if( HavePort ) {
        par1284Command.CommandFlags = PAR_HAVE_PORT_KEEP_PORT;
    } else {
        par1284Command.CommandFlags = 0;
    }

    pdoType = Pdx->PdoType;
    switch( pdoType ) {
    case PdoTypeRawPort:
    case PdoTypeEndOfChain:
        par1284Command.ID = 0; // ignored, but set anyway
        par1284Command.CommandFlags |= PAR_END_OF_CHAIN_DEVICE;
        break;
    case PdoTypeLegacyZip:
        par1284Command.ID = DOT3_LEGACY_ZIP_ID;
        break;
    case PdoTypeDaisyChain:
        par1284Command.ID = Pdx->Ieee1284_3DeviceId;
        break;
    default:
        DD((PCE)Pdx,DDE,"Invalid pdoType = %x\n",pdoType);
        PptAssert(FALSE);
        break;
    }

    pPortDeviceObject = Pdx->PortDeviceObject;

    //
    // Send the request
    //
    timeOut.QuadPart = -(10*1000*500); // 500ms ( 100ns units )

    status = ParBuildSendInternalIoctl(IOCTL_INTERNAL_SELECT_DEVICE,
                                       pPortDeviceObject,
                                       &par1284Command, sizeof(PARALLEL_1284_COMMAND),
                                       NULL, 0,
                                       &timeOut);

    if( NT_SUCCESS( status ) ) {
        // SELECT succeeded
        DD((PCE)Pdx,DDT,"ParSelectDevice - SUCCESS\n");
        if( !HavePort ) {
            // note in the device extension that we have the port
            Pdx->bAllocated = TRUE;
        }
        return TRUE;
    } else {
        // SELECT failed
        DD((PCE)Pdx,DDT,"ParSelectDevice - FAIL\n");
        return FALSE;
    }
}

BOOLEAN
ParDeselectDevice(
    IN  PPDO_EXTENSION  Pdx,
    IN  BOOLEAN         KeepPort
    )
/*++

Routine Description:

    This routine deselects a 1284.3 or Legacy Zip device and optionally
    releases the ParPort

Arguments:

    Pdx   - Supplies the device extension.

    KeepPort    - TRUE  indicates that we should keep the port acquired,
                    so we should only do a DESELECT_DEVICE
                - FALSE indicates that we should not keep the port acquired,
                    so we should do a combination DESELECT_DEVICE/FREE_PORT

Return Value:

    TRUE    - The device was deselected (and the port released if requested)

--*/
{
    PARALLEL_1284_COMMAND       par1284Command;
    NTSTATUS                    status;
    enum _PdoType               pdoType;
    PDEVICE_OBJECT              fdo = Pdx->Fdo;
    PFDO_EXTENSION              fdx = fdo->DeviceExtension;

    //
    // If we don't have the port, succeed and return
    //
    if( !Pdx->bAllocated ) {
        DD((PCE)Pdx,DDW,"ParDeselectDevice - we do not have the port\n");
        return TRUE;
    }

    //
    // Initialize command structure and extract parameters from the DeviceExtension
    //

    // reserved - always set to 0
    par1284Command.Port = 0;

    if( KeepPort ) {
        par1284Command.CommandFlags = PAR_HAVE_PORT_KEEP_PORT;
    } else {
        par1284Command.CommandFlags = 0;
    }

    pdoType = Pdx->PdoType;
    switch( pdoType ) {
    case PdoTypeRawPort:
    case PdoTypeEndOfChain:
        par1284Command.ID = 0; // ignored, but set anyway
        par1284Command.CommandFlags |= PAR_END_OF_CHAIN_DEVICE;
        break;
    case PdoTypeLegacyZip:
        par1284Command.ID = DOT3_LEGACY_ZIP_ID;
        break;
    case PdoTypeDaisyChain:
        par1284Command.ID = Pdx->Ieee1284_3DeviceId;
        break;
    default:
        DD((PCE)Pdx,DDE,"Invalid pdoType = %x\n",pdoType);
        par1284Command.ID = 0; // choose a 1284.3 type deselect since this is harmless
        PptAssert(FALSE);
        break;
    }

    status = PptDeselectDevice( fdx, &par1284Command );

    if( status != STATUS_SUCCESS ) {
        // DESELECT failed?!? - there isn't anything that we can do
        DD((PCE)Pdx,DDE,"ParDeselectDevice - FAILED - nothing we can do - status=%x\n", status);
    } else {
        DD((PCE)Pdx,DDT,"ParDeselectDevice - SUCCESS\n", status);
    }

    if( !KeepPort ) {
        // note in the device extension that we gave up the port
        DD((PCE)Pdx,DDT,"ParDeselectDevice - gave up port\n");
        Pdx->bAllocated = FALSE;
    }

    return TRUE;
}